It has been found that cardiac monitoring, pacing, cardioversion and defibrillation can be performed using electrodes carried on catheters placed within the esophagus. Esophageal catheters are often preferred because they are less expensive, less risky, much easier and faster than surgical methods or other methods of placing electrodes close to or on the heart. Esophageal catheters are more direct, more sensitive, and often easier than methods involving the use of external electrodes. Thus, esophageal catheters can be advantageously used in emergency situations or temporary situations such as during surgery.
When using esophageal catheters, it is necessary to get good electrical conductivity between electrodes carried on the catheters and the wall of the esophagus. It is presently typical to place the electrode directly against the wall of the esophagus. One problem with doing so is the potential for current burns to occur at the point of contact between the electrode and the esophagus wall, especially when performing defibrillation.
The problem of current burn can be reduced or eliminated by using an electrode with a large surface area. However, a large electrode is more difficult to insert into the esophagus, and it is not convenient.
I have invented a novel type of esophageal catheter, which reduces or eliminates the potential for catheter burn, and which can be made small and thin for easy, quick and convenient use.
An object of the present invention is to provide an esophageal catheter useful in cardiac monitoring, pacing, cardioversion and/or defibrillation with reduced risk of current burn, and which has a small outer diameter.
Another object is to provide an improved esophageal catheter that is easy and economical to construct and is simple and convenient to use.
Other objects and advantages of the present invention will become apparent as the description proceeds.